A series of novel emissive Ir(III) complexes having the coordination environments of [Ir(N--N--N)2]3+, [Ir(N--N--N)(N--N)Cl]2+, and [Ir(N--N--N)(N--C--N)]2+ with 2,6-bis(1-methyl-benzimidazol-2-yl)pyridine (L1, N--N--N), 1,3-bis(1-methyl-benzimidazol-2-yl)benzene (L2H, N--C--N), 4'-(4-methylphenyl)-2,2':6',2' '-terpyridine (ttpy, N--N--N), and 2,2'-bipyridine (bpy, N--N) have been synthesized and their photophysical and electrochemical properties studied. The Ir(III) complexes exhibited phosphorescent emissions in the 500-600 nm region, with lifetimes ranging from approximately 1-10 micros at 295 K. Analysis of the 0-0 energies and the redox potentials indicated that the lowest excited state of [Ir(L1)(L2)]2+ possessed the highest contribution of 3MLCT (MLCT = metal-to-ligand charge transfer) among the Ir(III) complexes, reflecting the sigma-donating ability of the tridentate ligand, ttpy < L1 < L2. The emission quantum yields (phi) of the Ir(III) complexes ranged from 0.037 to 0.19, and the highest phi value (0.19) was obtained for [Ir(L1)(bpy)Cl]2+. Radiative rate constants (k(r)) were 1.2 x 10(4) s(-1) for [Ir(ttpy)2]3+, 3.7 x 10(4) s(-1) for [Ir(L1)(bpy)Cl]2+, 3.8 x 10(4) s(-1) for [Ir(ttpy)(bpy)Cl]2+, 3.9 x 10(4) s(-1) for [Ir(L1)2]3+, and 6.6 x 10(4) s(-1) for [Ir(L1)(L2)]2+. The highest radiative rate for [Ir(L1)(L2)]2+ with the highest contribution of 3MLCT could be explained in terms of the singlet-triplet mixing induced by spin-orbit coupling of 5d electrons in the MLCT electronic configurations.

Magnetic orientation of isotactic polystyrene during the isothermal crystallization at 210 °C in the magnetic field of 6 T is studied by using the magnetic birefringence, X-ray diffraction, and infrared measurements. The orientation starts in the vicinity of the end of the induction period, that is, before the crystal growth is observed by the wide angle X-ray diffraction This suggests that some anisotropic structures formed in the induction period are responsible for the magnetic orientation. Crystals formed are aligned with the c-axis, perpendicular to the magnetic field. Crystallization process is accelerted under the magnetic field.

A two-dimensional numerical study on a daytime sea-breeze front was carried out in order to investigate the interaction of the sea-breeze front with Benard-Rayleigh-type convective cells within the wellmixed boundary layer ahead of the sea-breeze front. By using a nonhydrostatic compressible dry model with a very fine spatial resolution, it was found that either a frontogenesis (FG), or a frontolysis (FL) phenomenon, occurs alternately at the foremost part of the sea-breeze head. Through these interactions, the propagation speed of the sea-breeze front varied discontinuously. The frontal structure such as the shape, vertical velocity, temperature field and so on showed periodic variations as it was affected by upward and downward motions associated with the prefrontal convective cells. Based on horizontal distribution of the vertical velocity, the periodic variation was classified into three stages: FG, transition, and FL stages. For each stage, the detailed processes of FG and FL phenomena were examined by estimating each term of the frontogenesis equation. It is found that the confluence, and tilting terms, play an important role in the FG and FL processes.

It has been suggested that colostrum is important not only for direct protection from pathogens but also for proper development of immune systems in piglets. In this study, we focused on the effect of colostrum ingestion during the first 24 h of life on early postnatal development of piglet immune systems. Thirty-six piglets from five litters were divided into colostrum-fed (CoF) and colostrum-deprived (CoD) groups. The former group was allowed to suckle normally while formula milk was fed to the latter group during the first 24 h of life. At the weaning period, the concentrations of fecal immunoglobulin (Ig) A and plasma IgG as well as the number of blood leukocyte subsets were analyzed. Fecal IgA and plasma IgG concentrations in the CoF group were more than twice as high as those in the CoD group (P < 0.01). In addition, the number of blood B cells was significantly higher in the CoF group than that in the CoD group (P < 0.05). This study demonstrates that colostrum ingestion during the first 24 h plays a significant role in early postnatal development of both mucosal and systemic immunity of piglets.